Problem:if I firstly insert my kmod_test.ko, then insert eventfd_link.ko,
error will happen with hint "Device or resource busy". This is because
the default minor device number, 0, has been occupied by my kmod_test.ko .
root@distro:~/test$ lsmod
Module Size Used by
kmod_test 927 0
vboxsf 35930 4
vboxguest 222130 1 vboxsf
microcode 10315 0
autofs4 25051 0
root@distro:~/test$ insmod ./eventfd_link.ko
insmod: ERROR: could not insert module ./eventfd_link.ko: Device or
resource busy
Explanation: For miscdevices, the major device_no is same, so the minor
device_no should be set to ditinguish different misc devices; if not set
the minor, it may fail while insmod due to the default minor value, 0, has
been used by other miscdevice. MISC_DYNAMIC_MINOR means to let Linux
kernel dynamically assign one minor devide number while loading.
Signed-off-by: Xiaobo Chi <xiaobo.chi@nokia.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
7836894a64